Collar versus collarless cemented HD-II femoral prostheses

A randomized prospective study was done in 1982 to evaluate the effect of a collar on the cemented femoral component. During a 2-year period, 84 patients were enrolled to receive a collared (44 hips) or a collarless (40 hips) HD-II femoral component at the time of their primary total hip arthroplasty. Three patients were lost to followup, two patients were excluded because of randomization errors, six patients had good clinical results but refused followup, and 30 patients had died. The 43 surviving patients (collar 24, collarless 19) had radiographic and clinical followups at an average of 9.6 years (range, 61-143 months). Harris hip scores were similar, with an average of 89 in the collared group and 78 in the collarless group. There were no differences in the incidence or magnitude of pain between the patients receiving a collared or collarless femoral component. The Kaplan-Meier survivorship analysis predicted an overall survival rate free of revision of 86% at 10 years. There were no statistically significant differences in survival rates between the two groups.